Joseph m



(N9 ModeL) J. M. DUNCAN.

FURNACE GRATE.

No. 321,890. Patented 511177, 1885.

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JOSEPH M. DUNCAN, OF WARSAW, NEW YORK, ASSIGNOR TO HIMSELF f AND EBEN O.MONAIR, QF SAME PLACE.

RNACE GRATE.

SPECIFICATION forming part of Letters PatentNo. 321,890, dated July '7,1885.

Application filed March 16, 1855. (N0 model.)

To all whom it may concern:

Be it known that I, J OSEPH M. DUNCAN, of WVarsaw, in the county ofWVyoming and State of New York, have invented a new and usefulImprovement in Furnace-Grates; and I do hereby declare that thefollowingis a full and exact description of the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon.

My invention relates to improvements in grates for furnaces; and itsobject is to render the same self-feeding and self-discharging for thepurpose of saving labor as well as giving better combustion. It is wellknown that the frequent opening of furnace-doors for feeding andraking-purposes admits a large amount of cold air to the surface of thefire,whieh deadens the same,besides injuringthe combustion, and infurnaces fed by hand they necessarily have to be raked out at least onceevery six hours, which cools the walls and lessens the amount ofevaporation. WVith myimprovements these causes and objections areremoved,and a clean fire is constantly maintained with much less orcomparatively no labor.

The novelty of these improvements consists in a revolving or otherwisetraveling grate,

. tion to a furnace,

rear end.

combined with conveyors arranged at the rear and front ends of thefurnace; and it further consists in means for supporting and operatingthe same, together with other details of construction and arrangement,all as more fully hereinafter described, and set forth in the claims.

For the better understanding of my improved devices, together with theirmode of applicaattention is invited to the accompanying drawings, inwhich Figure 1 is a transverse section of afurnace provided with grateand conveyer-s constructed and arranged in accordance with myinvention;Fig. 2, a similar view of a modification; Fig. 3, a side elevation,partly broken away, of the furnace shown in Fig. 1; Fig. 4, a deu tailof a section of the grate.

Like letters of reference denote corresponding parts in the views.

A denotes an ordinary furnace with a door, B, at its front end, and abridge-wall, O, at its Three or more pairs of sprocketwheels, D D, arearranged in the interior,next

to the side walls of the furnaee,upon shafts a,

running in the same plane parallel to each other and having bearings insaid side walls. These wheels carry a pair of endless chain belts orsprocket-chains, D D, to which are secured the ends of a series oftransverse perforated bars, I) I), made from east or wrought iron, witheither a flat or corrugated upper surface, and these bars, together withthe chains D D, constitute the grate proper. The shafts to extendthrough the sides of the furnace, and are provided on their outer endswith additional sprocket-wheels, E E, and an endlesschain belt orsprocket-chain, E, for each set of said wheels, whereby the strain isevenly distributed on all the shafts and wheels. One of the shafts a isfarther extended at one end, and has any suitable wheel or pulley,withappropriate connections with the d riving-power. The grate-surfaceproper is level, or nearly so, and on the revolution of thedriving-shaft the chains, together with the grate, travel from the reartoward the front of the furnace. All coal is fed upon the revolvinggratein the rear of the bridge-wall C by means of a conveyer,represented at F, which should be so arranged as to supply the grateuniformly at a speed relative to that of the grate. This conveyer iscovered and protected from the heat by the bridgewall, over which theflames pass without affecting the fresh coal, except when such coalshall have been carried out from under the bridge-wall. Thedriving-power should be under such control as to regulate the speed ofthe grate, to the end that the coal shallhave been consumed by the timeit reaches theshaft a at thefront of thefurnace,where itis dumped anddeposited in a conveyer or receiver, F, similar to the one at the rearend under the bridge-wall of the furnace.

In a furnace with no bridge-wall, or when it is desirable, the grate (bythe use of extra sprocket-wheels D D arranged as shown in Fig. 2) may bemade to rise 011a gentle incline upward on its return to the point whereit commences to travel on a level. \Vith this change the conveyer forfeeding the coal is arranged below the level of the grate proper, andthis, then, allows a free passage of the smoke and certain cireumstances.

By my improved grate the fresh coal is constantly being carried into thehottest of the fire,

and is entirely consumed by thetime it reaches the front of the furnace,thus maintaining a fresh clean fire at all times without raking the sameor opening the furnace-doors; and it will be seen that this grate, withits supporting and carrying devices, is protected from the heat by thecold air which enters from the draftopenings at the front, and they arethereby rendered more durable.

Having thus described I claim, and desire to out, is

l. The combination, in a furnace, of a traveling grate, a conveyor forfeeding the coal, and a conveyor for receiving the ashes, substantiallyas described.

2. The combination, in a furnace, of a traveling grate, and a conveyorfor receiving the ashes at the front end, substantially as described.

3. The combination, in afurnace, ofa travmy invention, what secure byLetters Pateling grate, a conveyer for feeding coal from the rear of thefire, and a conveyer for receiving the ashes at the front end,substantially as described.

4. The combination, with a furnace, of a traveling grate arranged tocarry the fuelupward on an incline from the rear of the fire, and thenceon a level to the front of the furnace, substantially as and for thepurposes set forth.

5. The combination, in a furnace, of a traveling grate moving onanincline and on a level, and a conveyer for feeding the coal, arrangedbelow the top level of said grate, substantially as described.

6. The combination, in a furnace, of a set of sprocket wheels andchains, a series of perforated grate-bars secured to said chains, andanother set of sprocket wheels and chains on the outside of the furnace,substantially as and for the purposes set forth.

In testimony whereof I afiix my signature in presence of two witnesses.

JOSEPH M. DUNCAN.

\Vitnesses:

E. O. MoNAIR, \VM. H. MoCoNNnLL.

